112 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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| This file is part of Telegram Desktop,
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| the official desktop application for the Telegram messaging service.
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| 
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| For license and copyright information please follow this link:
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| https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
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| */
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| #pragma once
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| 
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| #include <QtCore/QLatin1String>
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| 
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| namespace base {
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| 
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| template <typename Type>
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| inline Type take(Type &value) {
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| 	return std::exchange(value, Type {});
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| }
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| 
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| template <typename Type>
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| inline Type duplicate(const Type &value) {
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| 	return value;
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| }
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| 
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| template <typename Type, size_t Size>
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| inline constexpr size_t array_size(const Type(&)[Size]) {
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| 	return Size;
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| }
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| 
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| template <typename Container, typename T>
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| inline bool contains(const Container &container, const T &value) {
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| 	const auto end = std::end(container);
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| 	return std::find(std::begin(container), end, value) != end;
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| }
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| 
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| template <typename D, typename T>
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| inline constexpr D up_cast(T object) {
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| 	using DV = std::decay_t<decltype(*D())>;
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| 	using TV = std::decay_t<decltype(*T())>;
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| 	if constexpr (std::is_base_of_v<DV, TV>) {
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| 		return object;
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| 	} else {
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| 		return nullptr;
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| 	}
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| }
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| 
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| // We need a custom comparator for set<std::unique_ptr<T>>::find to work with pointers.
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| // thanks to http://stackoverflow.com/questions/18939882/raw-pointer-lookup-for-sets-of-unique-ptrs
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| template <typename T>
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| struct pointer_comparator {
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| 	using is_transparent = std::true_type;
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| 
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| 	// helper does some magic in order to reduce the number of
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| 	// pairs of types we need to know how to compare: it turns
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| 	// everything into a pointer, and then uses `std::less<T*>`
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| 	// to do the comparison:
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| 	struct helper {
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| 		const T *ptr = nullptr;
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| 		helper() = default;
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| 		helper(const helper &other) = default;
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| 		helper(const T *p) : ptr(p) {
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| 		}
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| 		template <typename ...Ts>
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| 		helper(const std::shared_ptr<Ts...> &other) : ptr(other.get()) {
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| 		}
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| 		template <typename ...Ts>
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| 		helper(const std::unique_ptr<Ts...> &other) : ptr(other.get()) {
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| 		}
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| 		bool operator<(helper other) const {
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| 			return std::less<const T*>()(ptr, other.ptr);
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| 		}
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| 	};
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| 
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| 	// without helper, we'd need 2^n different overloads, where
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| 	// n is the number of types we want to support (so, 8 with
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| 	// raw pointers, unique pointers, and shared pointers).  That
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| 	// seems silly.
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| 	// && helps enforce rvalue use only
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| 	bool operator()(const helper &&lhs, const helper &&rhs) const {
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| 		return lhs < rhs;
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| 	}
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| 
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| };
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| 
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| inline QString FromUtf8Safe(const char *string, int size = -1) {
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| 	if (!string || !size) {
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| 		return QString();
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| 	} else if (size < 0) {
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| 		size = strlen(string);
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| 	}
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| 	const auto result = QString::fromUtf8(string, size);
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| 	const auto back = result.toUtf8();
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| 	return (back.size() != size || memcmp(back.constData(), string, size))
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| 		? QString::fromLocal8Bit(string, size)
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| 		: result;
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| }
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| 
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| inline QString FromUtf8Safe(const QByteArray &string) {
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| 	return FromUtf8Safe(string.constData(), string.size());
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| }
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| 
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| } // namespace base
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| 
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| template <typename T>
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| inline void accumulate_max(T &a, const T &b) { if (a < b) a = b; }
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| 
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| template <typename T>
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| inline void accumulate_min(T &a, const T &b) { if (a > b) a = b; }
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| 
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| template <size_t Size>
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| QLatin1String qstr(const char(&string)[Size]) {
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| 	return QLatin1String(string, Size - 1);
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| }
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